Various types of radio communication systems in accordance with the 3GPP (Third Generation Partnership Project) standard are in use. In the radio communication system that complies with the LTE/SAE (Long Term Evolution/System Architecture Evolution) standard with 3GPP, a logical communication path (user-plane path) used for user data communication is established between a gateway device and user equipments, via an eNB (evolved Node B), which is a radio base station. User equipments can perform communication with an external network (the Internet, etc.), using the established U-Plane path.
The eNB has a communication path (control-plane path) for transmitting and receiving control signals to and from other eNBs, a switching station, and a user equipment. An eNB, when it is radio-connecting with a user equipment and when the user equipment moves to a cell which a different eNB forms, transmits and receives control messages to and from the user equipment and the different eNB via a control-plane path, and operates so as to make the user equipment handover to the different eNB. When the user equipment is handed over, a user-plane path is changed so as to pass an eNB to which the user equipment is handed over.